A balanced flow-through viscosity sensor based on a torsionally resonating pipe

In this paper we present a new balanced flowthrough viscosity sensor working with a torsionally resonating pipe. The whole system is machined in aluminum and is designed to be placed in the pipes of a chemical production plant. The quality factor Q and the resonance frequency fr are used as measures for the viscosity and density. We describe the sensor setup, its working principle for different resonant modes, the actuation and the readout of the sensor and present first measurement results for liquids featuring different viscosities.